Dr. Michael P. Gillespie

The adult human skeleton consists of 206 named bones.

Infants have more bones because not all bones have fused.

Axial skeleton – 80 bonesLongitudinal axis (center of the body)Bones arranged along the axis: skull bones,

auditory ossicles, hyoid bone, ribs, breastbone, and backbone

Appendicular skeleton – 126 bonesUpper and lower limbs (extremities), girdles

(connect limbs to axial skeleton)

SkullCranium 8Face 14

Hyoid 1Auditory Ossicles 6Vertebral Column 26Thorax

Sternum 1Ribs 24

Total 80

Pectoral (Shoulder) girdlesClavicle 2Scapula 2

Upper limbs (extremities)Humerus 2Ulna 2Radius 2Carpals 16Metacarpals 10Phalanges 28

Pelvic (hip) girdleHip, pelvic, or coxal bones 2

Lower limbs (extremities)Femur 2Fibula 2Tibia 2Patella 2Tarsals 14Metatarsals 10Phalanges 28

Total 126

Long BonesShort BonesFlat BonesIrregular BonesSesamoid BonesSutural

Depressions and OpeningsSites allowing the passage of soft tissue

(nerves, blood vessels, ligaments, tendons) or formation of joints.

ProcessesProjections or outgrowths on bone that form

joints or attachment points for connective tissue, such as ligaments and tendons).

Fissure – narrow slitForamen – opening (hole)Fossa – shallow depression (trench)Sulcus – furrow (groove)Meatus – tubelike opening (passageway)

Processes that form jointsCondyle – Large, round protuberance at the

end of a bone (knuckle)Facet – smooth, flat articular surfaceHead – rounded articular projection supported

on the neck of a bone

Processes that form attachment pointsCrest – prominent ridge or elongated

projectionEpicondyle – projection above a condyleLine – long narrow ridge or borderSpinous process – sharp, slender projectionTrochanter – very large projectionTubercle – small, rounded projectionTuberosity – large, rounded projection

Carotid Hypoglossal Infraorbital Jugular Lacerum Magnum Mandibular

MastoidMentalOlfactoryOpticOvaleRotundumStylomastoidSupraorbital

Membrane-filles spaces between the cranial bones

“soft spots”Allow the skull to change shape as it passes

through the birth canal

Anterior fontanelBetween the parietal bones and the frontal

bonePosterior fontanel

Between the parietal bones and the occipital bone

Anterolateral fontanelsBetween the frontal, parietal, temporal, and

sphenoid bonesPosterolateral fontanels

Between the parietal, occipital, and temporal bones

Kyphosis – exaggeration of the thoracic curve

Lordosis – an exaggeration of the lumbar curve or cervical curve

Lumbar spine stenosis – narrowing of the spinal canal

Scoliosis – lateral bending of the vertebral column